Add pimped coredns config file to request resolver with '/etc/resolv.conf' internal server and bypass internal kubernetes resolver

coredns.yaml

@@ -0,0 +1,222 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: coredns
+  namespace: kube-system
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  labels:
+    kubernetes.io/bootstrapping: rbac-defaults
+  name: system:coredns
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - endpoints
+  - services
+  - pods
+  - namespaces
+  verbs:
+  - list
+  - watch
+- apiGroups:
+  - discovery.k8s.io
+  resources:
+  - endpointslices
+  verbs:
+  - list
+  - watch
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  annotations:
+    rbac.authorization.kubernetes.io/autoupdate: "true"
+  labels:
+    kubernetes.io/bootstrapping: rbac-defaults
+  name: system:coredns
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: system:coredns
+subjects:
+- kind: ServiceAccount
+  name: coredns
+  namespace: kube-system
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: coredns
+  namespace: kube-system
+data:
+  Corefile: |
+    .:53 {
+        errors
+        health
+        ready
+        kubernetes cluster.local in-addr.arpa ip6.arpa {
+          pods insecure
+          fallthrough in-addr.arpa ip6.arpa
+        }
+        hosts /etc/coredns/NodeHosts {
+          ttl 60
+          reload 15s
+          fallthrough
+        }
+        prometheus :9153
+        cache 30
+        loop
+        reload
+        loadbalance
+        import /etc/coredns/custom/*.override
+        forward . /etc/resolv.conf
+    }
+    import /etc/coredns/custom/*.server
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: coredns
+  namespace: kube-system
+  labels:
+    k8s-app: kube-dns
+    kubernetes.io/name: "CoreDNS"
+spec:
+  revisionHistoryLimit: 0
+  strategy:
+    type: RollingUpdate
+    rollingUpdate:
+      maxUnavailable: 1
+  selector:
+    matchLabels:
+      k8s-app: kube-dns
+  template:
+    metadata:
+      labels:
+        k8s-app: kube-dns
+    spec:
+      priorityClassName: "system-cluster-critical"
+      serviceAccountName: coredns
+      tolerations:
+        - key: "CriticalAddonsOnly"
+          operator: "Exists"
+        - key: "node-role.kubernetes.io/control-plane"
+          operator: "Exists"
+          effect: "NoSchedule"
+      nodeSelector:
+        kubernetes.io/os: linux
+      topologySpreadConstraints:
+        - maxSkew: 1
+          topologyKey: kubernetes.io/hostname
+          whenUnsatisfiable: DoNotSchedule
+          labelSelector:
+            matchLabels:
+              k8s-app: kube-dns
+        - maxSkew: 1
+          topologyKey: topology.kubernetes.io/zone
+          whenUnsatisfiable: ScheduleAnyway
+          labelSelector:
+            matchLabels:
+              k8s-app: kube-dns
+      containers:
+      - name: coredns
+        image: "rancher/mirrored-coredns-coredns:1.14.1"
+        imagePullPolicy: IfNotPresent
+        resources:
+          limits:
+            memory: 170Mi
+          requests:
+            cpu: 100m
+            memory: 70Mi
+        args: [ "-conf", "/etc/coredns/Corefile" ]
+        volumeMounts:
+        - name: config-volume
+          mountPath: /etc/coredns
+          readOnly: true
+        - name: custom-config-volume
+          mountPath: /etc/coredns/custom
+          readOnly: true
+        ports:
+        - containerPort: 53
+          name: dns
+          protocol: UDP
+        - containerPort: 53
+          name: dns-tcp
+          protocol: TCP
+        - containerPort: 9153
+          name: metrics
+          protocol: TCP
+        securityContext:
+          allowPrivilegeEscalation: false
+          capabilities:
+            add:
+            - NET_BIND_SERVICE
+            drop:
+            - all
+          readOnlyRootFilesystem: true
+        livenessProbe:
+          httpGet:
+            path: /health
+            port: 8080
+            scheme: HTTP
+          initialDelaySeconds: 60
+          periodSeconds: 10
+          timeoutSeconds: 1
+          successThreshold: 1
+          failureThreshold: 3
+        readinessProbe:
+          httpGet:
+            path: /ready
+            port: 8181
+            scheme: HTTP
+          initialDelaySeconds: 0
+          periodSeconds: 2
+          timeoutSeconds: 1
+          successThreshold: 1
+          failureThreshold: 3
+      dnsPolicy: Default
+      volumes:
+        - name: config-volume
+          configMap:
+            name: coredns
+            items:
+            - key: Corefile
+              path: Corefile
+            - key: NodeHosts
+              path: NodeHosts
+        - name: custom-config-volume
+          configMap:
+            name: coredns-custom
+            optional: true
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: kube-dns
+  namespace: kube-system
+  annotations:
+    prometheus.io/port: "9153"
+    prometheus.io/scrape: "true"
+  labels:
+    k8s-app: kube-dns
+    kubernetes.io/cluster-service: "true"
+    kubernetes.io/name: "CoreDNS"
+spec:
+  selector:
+    k8s-app: kube-dns
+  clusterIP: 10.43.0.10
+  clusterIPs: [10.43.0.10]
+  ports:
+  - name: dns
+    port: 53
+    protocol: UDP
+  - name: dns-tcp
+    port: 53
+    protocol: TCP
+  - name: metrics
+    port: 9153
+    protocol: TCP
+  ipFamilyPolicy: SingleStack